The invention concerns ancillary devices, namely stand offs, which can be affixed to a conventional masonry or carpentry level to enable the level to be used to bridge imperfections or obstructions in the surface to be measured.
Often, it is desired to estimate the level between surface points but because the intermediate area is distorted, roughened or bowed, the level cannot be used. For example, this problem commonly occurs with wood which, due to excessive moisture or uncontrolled drying, has bowed. It also occurs during construction of masonry walls (e.g., brick, stone, etc.) where because of the surface roughness, or joint compounds, a conventional level cannot be conveniently used.
A particularly unique problem occurs with brick walls where, during construction, the separate corners are slightly out of "plumb." In the past, the next course of brick would be layed up to equalize the difference between the different corner heights. This can only be done by those highly skilled practioners who have had sufficient experience with this type of problem so as to be able to gradually equalize the differences without distorting the appearance of the wall.
Accordingly, it is an object of this invention to provide portable devices which can be slipped onto a level and thereon adjusted to suit particular conditions of a surface to be measured and act as a stand off to bridge distorted intermediate regions on the measured surface.
The foregoing object as well as others are achieved in accordance with my invention which comprises a pair of slidably mounted stand offs. Conventional masonry and carpentry levels employ "I" beam construction and my stand offs are specifically designed to work with them. Each stand off includes a spring-tensioned clamp which is formed by the "in-turned-38 ends of a U-shaped member and an internal spring-tensioned shaft. The shaft, which has a disc mounted at one end to engage the in-turned ends, may be momentarily withdrawn under tension to allow the stand off to be easily slipped over either parallel side of the level. When the shaft is released the stand off is firmly positioned on the level and held there by the spring tension.
Importantly, the aforementioned problem of correcting for "out of plumb" corners may be solved using my invention. The slidable stand offs can be set to touch the true course point as well as the out of line elevation to give a new corrected line for successive courses of brick.